# CVE-2023-45288: HTTP/2 CONTINUATION flood in net/http > An attacker can cause denial of service in Go HTTP/2 endpoints by sending excessive CONTINUATION frames, forcing expensive header parsing. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Apr 2024 - **Updated:** 4 Nov 2025 - **Also known as:** ALSA-2024:1962, ALSA-2024:1963, ALSA-2024:2079, ALSA-2024:2699, AZL-38158, AZL-38173, AZL-38209, AZL-38233, AZL-38260, AZL-38281, AZL-38284, AZL-38302, AZL-38314, AZL-38338, AZL-38392, AZL-38395, AZL-38431, AZL-38473, AZL-38488, AZL-38503, AZL-38542, AZL-38569, AZL-38575, AZL-38581, AZL-38608, AZL-38623, AZL-38635, AZL-38659, AZL-38683, AZL-38692, AZL-38761, AZL-38785, AZL-38839, AZL-38878, AZL-38941, AZL-38950, AZL-38956, AZL-39004, AZL-39022, AZL-39154, AZL-39187, AZL-39202, AZL-39217, AZL-39223, AZL-39229, AZL-39232, AZL-39235, AZL-39238, AZL-39244, AZL-39259, AZL-39268, AZL-39274, AZL-39325, AZL-39334, AZL-39445, AZL-39463, AZL-39484, AZL-39487, AZL-39493, AZL-39505, AZL-39514, AZL-39550, AZL-39571, AZL-39625, AZL-39634, AZL-39678, AZL-39892, AZL-39984, AZL-42706, AZL-42864, AZL-43627, AZL-50336, BELL-CVE-2023-45288, BIT-golang-2023-45288, CLEANSTART-2026-CN84558, CLEANSTART-2026-EG08504, CLEANSTART-2026-ML87749, CLEANSTART-2026-PO33643, DEBIAN-CVE-2023-45288, ECHO-326d-6f7d-c967, GHSA-4v7x-pqxf-cx7m, GO-2024-2687, MGASA-2024-0128, MINI-2fgm-36mg-rg8x, MINI-4h8q-cgwr-cj59, MINI-4p5p-3m7c-hm69, MINI-4phm-rcff-8w2q, MINI-5hmh-6hg8-qw3q, MINI-5qrx-2qjc-97hp, MINI-79p2-33j7-h8pg, MINI-8jcc-45cq-mrpj, MINI-fxp4-pxwq-mww8, MINI-g5pr-h933-98qq, MINI-jh42-7v48-9q8w, MINI-p36j-8893-25f6, MINI-p647-ggh8-63p3, MINI-pgjm-j7j3-5xfx, OESA-2024-1488, RHSA-2024:1892, RHSA-2024:1899, RHSA-2024:1962, RHSA-2024:1963, RHSA-2024:2079, RHSA-2024:2625, RHSA-2024:2667, RHSA-2024:2671, RHSA-2024:2699, RHSA-2024:2892, RHSA-2024:2935, RHSA-2024:2936, RHSA-2024:4543, RHSA-2024:4545, RHSA-2024:4546, RHSA-2024:4933, RHSA-2024:4934, RLSA-2024:1962, RLSA-2024:2699, SUSE-SU-2024:1121-1, SUSE-SU-2024:1122-1, SUSE-SU-2024:1160-1, SUSE-SU-2024:1161-1, SUSE-SU-2024:2108-1, SUSE-SU-2024:3155-1, SUSE-SU-2025:0295-1, SUSE-SU-2025:0299-1, SUSE-SU-2025:0306-1, SUSE-SU-2025:0318-1, SUSE-SU-2025:0342-1, SUSE-SU-2025:0346-1, SUSE-SU-2025:0558-1, SUSE-SU-2025:0581-1, SUSE-SU-2026:20483-1, SUSE-SU-2026:20486-1, UBUNTU-CVE-2023-45288, openSUSE-SU-2024:13822-1, openSUSE-SU-2024:13823-1, openSUSE-SU-2024:13824-1, openSUSE-SU-2024:13837-1, openSUSE-SU-2024:13880-1, openSUSE-SU-2024:13881-1, openSUSE-SU-2024:13882-1, openSUSE-SU-2024:13989-1, openSUSE-SU-2024:14053-1, openSUSE-SU-2024:14399-1, openSUSE-SU-2024:14400-1, openSUSE-SU-2025:14709-1, openSUSE-SU-2025:14714-1, openSUSE-SU-2025:14744-1, openSUSE-SU-2025:15075-1, openSUSE-SU-2026:10090-1 ## What is CVE-2023-45288? CVE-2023-45288 is a high-severity denial of service vulnerability in golang.org/x/net/http2, published on 4 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames. Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed. This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send. The fix sets a limit on the amount of excess header frames we will process before closing a connection. ## Which versions are affected by CVE-2023-45288? 11 open source packages ship an affected version, including golang.org/x/net/http2, golang and golang.org/x/net. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `golang.org/x/net/http2` | Go | All versions | 0.23.0 | | `golang.org/x/net/http2` | Go | All versions | 0.23.0 | | `golang` | Bitnami | All versions | 1.21.9, 1.22.2 | | `golang.org/x/net` | Go | All versions | 0.23.0 | | `golang.org/x/net` | Go | All versions | 0.23.0 | | `golang.org/x/net` | Go | All versions | 0.23.0 | | `net/http` | Go | All versions | 1.21.9 | | `net/http` | Go | All versions | 1.21.9 | | `net/http` | Go | From 1.22.0-0 | 1.22.2 | | `net/http` | Go | From 1.22.0-0 | 1.22.2 | | `stdlib` | Go | All versions | 1.21.9, 1.22.2 | | `delve` | AlmaLinux:8 | All versions | 1.20.2-1.module_el8.9.0+3642+43318da8 | | `git-lfs` | AlmaLinux:8 | All versions | 3.2.0-3.el8_9 | | `go-toolset` | AlmaLinux:8 | All versions | 1.20.12-1.module_el8.9.0+3728+f1d47c6f | | `golang` | AlmaLinux:8 | All versions | 1.20.12-8.module_el8.9.0+3818+ac9bcae6 | | `golang-bin` | AlmaLinux:8 | All versions | 1.20.12-8.module_el8.9.0+3818+ac9bcae6 | | `golang-docs` | AlmaLinux:8 | All versions | 1.20.12-8.module_el8.9.0+3818+ac9bcae6 | | `golang-misc` | AlmaLinux:8 | All versions | 1.20.12-8.module_el8.9.0+3818+ac9bcae6 | | `golang-src` | AlmaLinux:8 | All versions | 1.20.12-8.module_el8.9.0+3818+ac9bcae6 | | `golang-tests` | AlmaLinux:8 | All versions | 1.20.12-8.module_el8.9.0+3818+ac9bcae6 | | `git-lfs` | AlmaLinux:9 | All versions | 3.2.0-2.el9_3 | | `go-toolset` | AlmaLinux:9 | All versions | 1.20.12-4.el9_3 | | `golang` | AlmaLinux:9 | All versions | 1.20.12-4.el9_3 | | `golang-bin` | AlmaLinux:9 | All versions | 1.20.12-4.el9_3 | | `golang-docs` | AlmaLinux:9 | All versions | 1.20.12-4.el9_3 | | `golang-misc` | AlmaLinux:9 | All versions | 1.20.12-4.el9_3 | | `golang-src` | AlmaLinux:9 | All versions | 1.20.12-4.el9_3 | | `golang-tests` | AlmaLinux:9 | All versions | 1.20.12-4.el9_3 | | `go-toolset-1.19-golang` | Red Hat:devtools:2023::el7 | All versions | 0:1.19.13-7.el7_9 | | `go-toolset-1.19-golang-bin` | Red Hat:devtools:2023::el7 | All versions | 0:1.19.13-7.el7_9 | | `go-toolset-1.19-golang-docs` | Red Hat:devtools:2023::el7 | All versions | 0:1.19.13-7.el7_9 | | `go-toolset-1.19-golang-misc` | Red Hat:devtools:2023::el7 | All versions | 0:1.19.13-7.el7_9 | | `go-toolset-1.19-golang-race` | Red Hat:devtools:2023::el7 | All versions | 0:1.19.13-7.el7_9 | | `go-toolset-1.19-golang-src` | Red Hat:devtools:2023::el7 | All versions | 0:1.19.13-7.el7_9 | | `go-toolset-1.19-golang-tests` | Red Hat:devtools:2023::el7 | All versions | 0:1.19.13-7.el7_9 | | `rhc-worker-script` | Red Hat:enterprise_linux:7::client | All versions | 0:0.8-1.el7_9 | | `rhc-worker-script` | Red Hat:enterprise_linux:7::server | All versions | 0:0.8-1.el7_9 | | `rhc-worker-script` | Red Hat:enterprise_linux:7::workstation | All versions | 0:0.8-1.el7_9 | | `delve` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.20.2-1.module+el8.9.0+18926+5193682d | | `delve-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.20.2-1.module+el8.9.0+18926+5193682d | ## How do I fix CVE-2023-45288? Upgrade golang.org/x/net/http2 to 0.23.0 or later. ## Is CVE-2023-45288 being exploited? There is no known exploitation of CVE-2023-45288 in the wild and no public exploit code. Public exploit code: - PoC for CVE-2023-45288, continuation flood vulnerability (github_poc): https://github.com/hex0punk/cont-flood-poc ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-45288 and fix it if it is affected. What it is: CVE-2023-45288 is a high-severity denial of service vulnerability in golang.org/x/net/http2, published on 4 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2023-45288 in the wild and no public exploit code. Affected packages and fixed versions: - golang.org/x/net/http2 (Go): affected all versions; fixed in 0.23.0 - golang.org/x/net/http2 (Go): affected all versions; fixed in 0.23.0 - golang (Bitnami): affected all versions; fixed in 1.21.9, 1.22.2 - golang.org/x/net (Go): affected all versions; fixed in 0.23.0 - golang.org/x/net (Go): affected all versions; fixed in 0.23.0 - golang.org/x/net (Go): affected all versions; fixed in 0.23.0 - net/http (Go): affected all versions; fixed in 1.21.9 - net/http (Go): affected all versions; fixed in 1.21.9 - net/http (Go): affected from 1.22.0-0; fixed in 1.22.2 - net/http (Go): affected from 1.22.0-0; fixed in 1.22.2 - stdlib (Go): affected all versions; fixed in 1.21.9, 1.22.2 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2023-45288/ (Markdown: https://insights.sbomify.com/CVE-2023-45288/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-45288 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-45288 - OSV: https://osv.dev/vulnerability/CVE-2023-45288 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-45288/ Summaries are generated and may contain mistakes; the official description above is the record.